By Ira DreyfussThe Associated Press
WASHINGTON  Strong abs don't necessarily build a flat stomach, but that doesn't stop people from trying. Beauty these days requires a six-pack.
"We have a psychological mind-set that if the abdominal region is trim, we are not obese," said researcher Peter Francis of San Diego State University. And if we are not obese, then we must be good-looking because modern America cherishes thinness, he said.
This seems to be what's behind America's search for better abs, said Francis, who rated stomach exercises with and without machines to help people do them. The research was done for the American Council on Exercise, a fitness advocacy group, as part of ACE's campaign to separate value from hype in exercise trends. The findings were in a May-June supplement to an ACE publication, FitnessMatters.
Francis and his colleagues at San Diego State's biomechanics lab hooked 30 healthy men and women ages 20 to 45 to electromyography equipment, which measures electrical activity generated as muscles work. The measurements let the researchers check the energy created in specific stomach muscles.
The scientists had the participants do 13 types of abs workouts  some with equipment, most without. The traditional crunch-style situp was used as the benchmark for the ratings.
The top-rated stomach strengthener was a no-equipment technique called the bicycle maneuver. To do it, the participant lies on the floor with the lower back pressed against the ground. The knees are then raised, and the exerciser starts moving his or her legs as if the exerciser were riding a bike.
The study found that the bicycle maneuver created almost 250 percent more muscle activity in the rectus abdominus muscles  the six-pack set  than a crunch did.
Second on the intensity list was the captain's chair. This exercise requires a pair of bars on which the exerciser can rest the forearms while letting the feet stay off the ground. The exerciser then lifts the knees toward the chest. The captain's chair was 212 percent more intense than a crunch.
Third, with a rating of 39 percent more intense, was use of an exercise ball  a large, squishy one on which an exerciser rests the back while doing situps.
Overall, exercises done on equipment did little better  and in some cases far worse  than exercises done without equipment. The Ab Roller, a metal frame that keeps a user in correct crunch position, was only 5 percent more beneficial than a crunch alone.
Rated worst was the Ab Rocker, a chairlike device that lets a person do abs work from a sitting position. It gave only 21 percent of the rectus abdominus benefit that could have been gained by doing standard crunches, the study found.
At TerraStar International in North Logan, Utah, company president Roger Dahle defended the device his organization distributes. By holding the body in proper crunch position, the user reduces the risk of injury from improper technique, and gains more from the workout, he said.
However, Dahle conceded that the risk of an injury from crunches is not great even without an Ab Roller. "If somebody can do a crunch with proper technique, it's debatable whether they need one," he said.
Calls to Body by Jake Enterprises, which distributes the Ab Rocker, were not returned.
But Francis was dubious about the need for equipment for exercises that require people to only move their abs. "We have been sold on the idea that products are worth more than knowledge," he said.
Abs work has benefits, said Stuart Rugg, a researcher at Occidental College in Los Angeles, who was not part of Francis' study. Torso strength helps to support the back and stabilizes the body. "It's an incredibly intelligent area to keep fit and lean," he said.
However, Rugg noted that abs work won't rip off the layer of fat in front of the muscles. That has to be done by diet and calorie-burning aerobic exercise, he said.
Worse from a point of view of looks, strengthening the stomach muscles without losing the fat may make the stomach seem even bigger, Rugg said. The stronger stomach wall can push out fat that may have previously sagged inward, he said.
A person can get strong stomach muscles without buying equipment  but if the equipment keeps the person motivated, Rugg had no problem with that. The problem was that equipment generally gets tried and forgotten.
Even Dahle, who has a virtually unlimited source of Ab Rollers, can testify to that. "I have to be honest. I do have one at home, but like everybody else, I have to use it more and stop hanging my clothes on it," he said.